Constantine I Copper-Alloy AE2

Monetary Context and Denominational Role

When Constantine I entered the imperial college upon the death of his father Constantius I in AD 306, the Roman monetary system established by Diocletian in AD 294 was undergoing intense fiscal strain. Diocletian's original base-metal nummus had been issued as a substantial billon piece weighing roughly 9 to 10 grams with an intentional silver content of approximately three to four percent. Accelerating inflation and treasury expenditure forced successive downward tariff adjustments and weight reductions throughout the early fourth century AD. Between AD 306 and roughly AD 313, mints in Britain, Gaul, Italy, and Illyricum scaled back the physical diameter of the nummus from its original 27-29 millimeter standard down to approximately 21-25 millimeters, placing these strikings into the modern numismatic category of AE2. Although ancient edicts rarely preserve the specific everyday terminology of the marketplace, this intermediate coin functioned as the primary low-denomination workhorse of retail trade and troop payments. The coin possessed a faint argentiferous surface enrichment achieved through chemical blanching of the planchets prior to striking, which gave fresh coins a bright, silver-like appearance before wear exposed the underlying copper alloy.

Production Technology and Mint Distribution

The manufacture of Constantinian AE2 bronzes was executed through centralized mints divided into multiple operating workshops (officinae). Each workshop maintained strict administrative accountability by placing distinct letters or symbols into the reverse exergue and fields. Blank preparation relied on casting rods or flattening cast bronze flans, which were then edge-trimmed to weight tolerances before striking with engraved iron dies under heavy hammer impact. Production of the AE2 module under Constantine was concentrated initially in the Western mints under his direct authority, most notably Augusta Treverorum (Trier), Londinium (London), and Lugdunum (Lyons). Following the defeat of Maxentius at the Battle of the Milvian Bridge in AD 312, Constantine brought the Italian and North African workshops at Rome, Ostia, and Ticinum into his network. Later campaigns against Licinius brought control over Siscia, Thessalonica, and eastern facilities. Trier served as the principal experimental mint, consistently leading adjustments in weight standard, artistic innovation, and alloy refinement during this transitional phase.

Obverse Iconography and Imperial Styles

The obverse portraits on Constantine I's AE2 coinage clearly document the transition between two distinct artistic paradigms. Early issues produced between AD 306 and AD 308 followed the Tetrarchic canon: stocky, cubic portraits featuring heavily lined brows, short cropped beards, blocky jaws, and intense gazes intended to project collective imperial resolve and shared authority. As Constantine consolidated his independent political identity, his die engravers revived a classicizing Julio-Claudian aesthetic. The ruler is depicted clean-shaven, with smooth facial contours, a prominent aquiline nose, and neatly arranged locks of hair curving toward the nape of the neck. Constantine appears wearing either a laurel wreath, an ornate helmet reflecting military leadership, or a jeweled diadem in later stages of his reign. The bust truncation varies across issues, appearing draped and cuirassed, bare-necked, or clad in an elaborate consular trabea accompanied by a handheld eagle-tipped sceptre.

Reverse Types and Ideological Themes

The reverse types found on the AE2 folles reflect the shifting political alliances and religious sensibilities of the early Constantinian administration. During his early years as Caesar and Augustus, Constantine retained the traditional Tetrarchic allegorical figure of the Genius of the Roman People, depicted standing with a patera and cornucopia. However, as ideological independence grew, this universal civic emblem was phased out in favor of personal divine protectors. Foremost among these was Mars, represented as Mars Pater Conservator or Mars Victor, standing in full armor with spear and shield to celebrate imperial victories over the Franks and Alamanni. By AD 310, following an imperial panegyric claiming a vision of Apollo, the cult of Sol Invictus became the dominant reverse motif. Sol is portrayed radiate and heroic, raising his right hand in blessing and cradling a globe in his left. Other reverse types commemorated imperial adventus entries, princeps iuventutis themes directed at Constantine's dynastic heirs, and military standards accompanied by captives.

Inscriptions and Epigraphic Formulas

Inscriptions on Constantinian AE2 bronzes adhered to rigid imperial titular conventions inscribed in classical Roman capital lettering. Obverse legends charted Constantine's constitutional elevation: early strikings read CONSTANTINVS NOB CAES (Nobilissimus Caesar) or FL VAL CONSTANTINVS NOB C, which subsequently advanced to CONSTANTINVS P F AVG (Pius Felix Augustus) and later IMP CONSTANTINVS P F AVG or CONSTANTINVS MAX AVG (Maximus Augustus). Reverse legends proclaimed imperial theology and state security. Typical formulae included GENIO POPVLI ROMANI, MARTI CONSERVATORI, MARTI PATRI PROPVGNATORI, and the prolific SOLI INVICTO COMITI, which celebrated the invincible sun as companion to the emperor. Exergual marks integrated mint abbreviations such as PTR or BTR (Trier), PLN (London), PLG (Lyons), or R S (Rome), often accompanied by symbols including stars, crescents, wreaths, or field letters indicating specific officina allocations.

Typology and Metrological Reductions

The chronology of Constantine I's AE2 module is defined by successive downward weight adjustments enacted between AD 306 and AD 313. In the initial phase (AD 306 to AD 307), the Western folles were struck to a theoretical standard of 1/48 of a Roman pound (approximately 6.8 grams) on broad 24-26 millimeter flans. In late AD 307, Constantine authorized a reduction to 1/72 of a Roman pound (roughly 4.5 grams) with modules settling strictly into the 21-24 millimeter span. This intermediate standard persisted through the dramatic civil war against Maxentius in AD 312. By AD 313, monetary authorities implemented a still sharper reduction to the 1/96 pound standard (approximately 3.4 grams) on flans dropping below 20 millimeters, transitioning the primary circulating bronze into the modern AE3 classification. Consequently, the true AE2 Constantinian bronze forms a discrete chronological horizon restricted primarily to the First and Second reductions of the western folles, alongside scarce medallic bronzes produced later in the reign.

Circulation Patterns and Hoard Contexts

Archaeological excavation and hoard evidence indicate that Constantinian AE2 coins circulated extensively across the western and central provinces of the empire. Massive deposits discovered in Britain, northern Gaul, the Rhine frontier, and Italy demonstrate that reduced folles moved fluidly along military supply networks and urban commercial centers. Hoards such as the Langtoft and Nether Compton deposits illustrate that populations readily accepted these reduced coins alongside older, heavier Tetrarchic nummi. Because the intrinsic silver content of the AE2 issues was minimal, their circulation value was maintained largely by state decree and institutional acceptance for taxes. As subsequent reforms further reduced bronze sizes to AE3 and AE4 modules after AD 318, AE2 coins frequently remained in circulation for decades, suffering extensive surface wear that rubbed away their initial silvery wash and blurred workshop control marks.

References

1. The Roman Imperial Coinage, Volume VII: Constantine and Licinius (A.D. 313-337). pp. 1-84, 154-296
2. Late Roman Bronze Coinage, A.D. 324-498. Part I, pp. 4-40
3. The Roman Imperial Coinage, Volume VI: From Diocletian's Reform (A.D. 294) to the Death of Maximinus (A.D. 313). pp. 88-142, 164-225